1. Field of the Invention
The present invention relates generally to a method for making a fruit-containing yogurt product having the appearance, texture and taste of conventional custard-type fruit-containing yogurt and, more specifically, to a method for making a fruit containing yogurt product having a fat, carbohydrate and calorie content significantly below that of conventional fruit-containing yogurt.
2. Description of the Prior Art
In recent years cultured milk products, referred to as yogurt, have enjoyed immense popularity. The beneficial effects on health due to the therapeutic properties of the bacterial cultures contained in yogurt are well known. In addition, yogurt has become a popular food among dieters. To increase its appeal, the sharp, tangy taste characteristic of plain, unflavored yogurt, which heretofore made yogurt unacceptable to many people, has been masked in many yogurt products with fruit and sweeteners. This practice has resulted in a flavored yogurt product that is more palatable to a wider segment of the population. However, the use of these additives has been accompanied by an increase in product calorie content from about 90 calories per eight ounce (224 grams) serving of plain, unflavored yogurt to about 250 to 270 calories per eight ounce (224 grams) serving of the sweetened, fruit-containing yogurt. Such a high calorie content renders the fruited product generally unsuitable for inclusion in reducing diets since the fruit yogurt uses up the majority of the calories usually alloted to a single meal. As a result the dieter has difficulty choosing a sufficient variety or quantity of foods to form a balanced meal within the remaining calories allowed. Accordingly, a need has developed for a fruit-containing yogurt product which is low in calories, fat and carbohydrate content.
Prior methods for producing sweetened or flavored yogurt have succeeded in obtaining a product with a relatively low butterfat content, for example, as low as the 0.5% butterfat content of ordinary skim milk, but none seem to have been able to produce a really low fat, less than about 0.5%, yogurt product having the characteristic creamy custard-type yogurt consistency while at the same time overcoming the high calorie and high carbohydrate problems accompanying the use of fruited or flavored yogurt. One reason for this is that yogurt previously made from really low fat milk products, less than about 0.5% butterfat, has been loose and watery and lacking in flavor rather than creamy and custard-like with consumer acceptable flavor, appearance and mouth feel. Efforts to overcome this problem to obtain a palatable product have either required adding flavor influencing milk solids, which increases the yogurt calorie content, or increasing the milk fat content, which has a similar effect.
Exemplary of prior methods for producing flavored yogurt is U.S. Pat. No. 3,969,534 to Pavey et al which teaches the production of the fruited, flavored yogurt which has relatively low, about 0.5% butterfat content. However, the product produced by the Pavey method does not appear to be low in carbohydrates or significantly lower in calories than conventional flavored yogurt. In U.S. Pat. No. 3,025,165, Metzger discloses a process for producing yogurt which uses relatively low butterfat starting materials, such as skim milk, to which is added about 1.5% to 6.4% of an unsaturated vegetable oil. As a result, a higher than desirable fat content for a reducing diet is obtained without significantly reducing the number of calories. Likewise, the fruited yogurt product produced by the process disclosed in U.S. Pat. No. 3,269,842 to Mayer et al has a fat content of about 4% and appears to be a high calorie, high carbohydrate product. Donay et al in U.S. Pat. No. 3,128,190, disclose the use of a skim milk starting material. However, the process for making Donay's fruit-containing yogurt requires fruit which is precooked with sucrose to prevent fermentation thereof by the yogurt cultures with resultant unpleasant flavors. As a result of this procedure the Donay et al method neither produces really low fat yogurt nor reduces the high calorie and carbohydrate content of fruit-containing yogurt. In U.S. Pat. No. 4,110,476, Rhodes discloses a process for preparing liquid, rather than custard-type, yogurt products which utilize whey protein concentrate together with milk products as the starting material ingredients and contain higher sugar contents than are desirable for a fruit-containing yogurt product suitable for a reducing diet.